How do I check which Minecraft version my server is running?

Your server's version decides which players can join, which plugins work and which Java you need. Yet the number is not always immediately visible. There are four ways to find it, from quick to thorough.

1. From the console

1. Go to the game panel and click your server.
2. Start the server if it is off and wait until it has fully started (you see Done! in the console).
3. Type about in the console and press Enter.
4. You get a line like This server is running Paper version 26.2-121 (MC: 26.2). The number after MC: is the Minecraft version; the number before it is the build of the server software.

On vanilla servers about does not exist; use version there. On Fabric and Forge servers /version works in-game, and the version is also in the first lines of the console at start-up.

2. In the panel

In the game panel, the Startup tab of your server shows which version was set when the server was created or at the last version switch. Note: that is the version the panel uses for the next (re)installation. If you uploaded a different jar yourself, the actual version can differ; the console is then the source of truth.

3. In the game's server list

Add your server to the multiplayer list and hover over the green connection icon on the right. If the server runs a different version than your client, Minecraft shows that version in red next to the player count, with the message Incompatible. Handy to quickly see whether a friend with an older or newer client can join.

4. From the jar file

Open File Manager in the panel. The name of the server file often reveals the version, for example paper-26.2-121.jar, or fabric-server-launch.jar with the version in fabric-server-launcher.properties. On Paper the version is also in the file version_history.json in the server folder, which keeps track of every version the world has ever been started on.

Players cannot join because of a version mismatch

The message Outdated server or Outdated client means client and server are not on the same version. You then have three options:

• Have players switch to the server's version (in the Minecraft Launcher you can pick any version).
• Update the server to the latest version, with a backup first and a check that your plugins support that version.
• Allow several versions at once with ViaVersion and ViaBackwards; how that works is in our blog article ViaVersion: players on different versions.

Switching versions

You change versions in the panel through the version selector; always make a backup first, because a world loaded on a newer version cannot safely go back to an older one. Since 26.1 the server also needs Java 25; which Java goes with which version is in which Java version your server needs.

Stuck, for example because the console shows no version with a modpack? Open a ticket and include the first twenty lines of the console; the version is almost always in there.